Semi-Aspirated Ballast System

[He Who Shall Not Be Named]

i wonder not about the outer float valve, but where the inner float valve will go, and how much air is inside the dry spaces

Reynolds Number aside, the system 'scales' well; what works as a 3.5 will work as a 2 sized SD.

But, as others pointed out here -- the limiting factor is finding room in the superstructure or sail for the float that operates the snorkel induction-valve. That item does not scale, it requires several ounces of buoyant force to shut it, no matter the size of the boat or SD it services.

Red boat has been exploring alternative float-linkage combinations and suggested a slide-valve type snorkel head-valve; something that is float activated but with a much smaller horizontal foot-print. Food for thought.

David

[Albion]

i will zip it :)

[He Who Shall Not Be Named]

i will zip it :)

No, no! ... keep it coming. Critical thinking involves exploration of all possibilities involved. Already Redboat has hit me with a potentially useful snorkel head-valve alternative. Would not have worked some of this stuff out without you guys putting stuff in front of me. Keep it coming, Albion.

My best work usually results after Andy, Ray, Carlos, Mike, Ron, Tom, you, or someone else with a brain kicked me in the teeth over a point I missed, or a wrong turn I've taken.

David

[MFR1964]

I think you guys are looking for this, a vertical floatvalve.





Even better for you, a close up picture, placed it on the V80, and replaced it for a example with lever action.
Why?, the leveraction will give you a better sealing, with this kind of floaters you are depending on the amount of floatingforce created by the styrodure, next issue will be the adding of lead to get it back in to it's position during a slight vacuum, this will cost you floatingforce.


Greetings Manfred.

[He Who Shall Not Be Named]

BINGO! ... and Manfred comes through again! Thank you so much for sharing.

I steal ideas only from the best, Manfred.

David

[MFR1964]

Hey, do i see the word stealing, where is my patentprotection, my copywright issue, whhaaaaaa, i want a lawyer

[He Who Shall Not Be Named]

Bill me!

David

[redboat219]

Can this vertical float valve be scaled down to fit a small boat?

As David mentioned I suggested to him an alternative snort mast sealing technique that does away with the long lever arm which activates the flapper valve. I remember reading that some commercial snorkeling gears which utilized valves which prevent water ingress. I typed in "float valve snorkel" and did an image search on Google and I came across this: http://www.ozeonsnorkeling.com/images/Snorkel-3.jpg

As you can see it has a flapper valve with a built in float which closes off the intake during a dive.

If look at it it's quite similar to what David made, the top end is just turned downward.
Taking idea from the drawing I asked Dave if it would be possible to just use the hinge and flap minus the arm and install it upside down and then glue a block of foam underneath the flapper valve to close it during submersion. The weight of the brass flap then opens the valve.

[Scott T]

How about this experiment. Take the float valve you have in the WTC and put the LPB hose on the top.
The bottom hole stays open to allow water in to raise the float on dive. There should also be a vent hole added
to the top to let air in and out as the water rises. A lite cup shaped chamber can be added to the float bottom
thats made of a pill bottle or other. The extra water in it will add weight to the float when it is raised into the air by surfacing.


Scott T

[He Who Shall Not Be Named]

How about this experiment. Take the float valve you have in the WTC and put the LPB hose on the top.
The bottom hole stays open to allow water in to raise the float on dive. There should also be a vent hole added
to the top to let air in and out as the water rises. A lite cup shaped chamber can be added to the float bottom
thats made of a pill bottle or other. The extra water in it will add weight to the float when it is raised into the air by surfacing.
[ATTACH=CONFIG]12414[/ATTACH]

Scott T

Interesting arrangement, Scott.

But, I see a flooding path through the open vent holes atop the safety float-valve.

Also, by taking a suction on the valve end of the safety float-valve unit you deny any air from the SD into the LPB should the induction line flood (which closes the valve).

In my current plumbing arrangement, if the safety float-valve is flooded, and the LPB takes a suction, then the partial vacuum it pulls on the flooded induction line will overcome the float pressure seating the upper safety float-valve element, permitting SD air into the safety float-valve, pulling the water out of it through the LPB and into the ballast tank, followed by SD air -- even with a flooded induction line. However, this only works if there is a 'slow' leak in the induction plumbing. If a collision carries away the snorkel head-valve, say, then you're screwed. But, at least you will have a dry SD sitting at the bottom of the pool/lake.

Something I've failed to mention, nor is apparent in the photos: the air/water path from the bottom outlet nipple to the upper inlet nipple of the safety float-valve is through the tight annular space between float and cylindrical body of the unit -- also, there is a blood-channel running the length of the float that offers a less obstructed path of air/water. Hence, no need for a vent atop the unit.

Or am I missing something here, and got your suggestion all wrong?

David

[Reckless]

please excuse the crude drawing that is not at all scale or a blue print .. LOL

but is this viable for the small nuke subs? (1/144 kilo/seawolf) .. or is this what one of the guys above was talking about?

I mean it's not like Dave has enough to do right now or anything ...

[He Who Shall Not Be Named]

Nice try, Rimbrandt.

Yes, this is pretty much the arrangement employed by Manfred and something I'm going to try as soon as I get a moment.

David

[redboat219]

David,
Just like Scott I had the idea of using one of your modified float valve assembly in lieu of the snort mast/ flapper valve (but still retaining the internal safety float valve). As Scott illustrated the suction line is connected to the top nipple. Some perforation are drill around the barrel to permit water or air entry.

Think this is much more compact than Manfred's.

[He Who Shall Not Be Named]

Stop the Presses!

Redboat put me straight -- I missed Scott T's point completely (and his drawings stated it, but I missed it). His drawings was of a snorkel head-valve. I was thinking safety float-valve when I wrote my comments.

Scott: I'm sorry. Now that my heads on straight I will indeed explore this arrangement, modified as you suggest, as a small foot-print snorkel head-valve. Good work. I'm a dope!

****!

David

[Scott T]

Now your thinking what I'm thinking! It uses your same basic design and could
cut down on different parts count.

If the weight of the float and cup won't break the vacuum maybe a monofiliment
could be used to open it with the reverse throw of the vent valve servo.

Scott T